Recording head feeding device



May 15, 1951 F. VAN EPS 2,553,392

RECORDING HEAD FEEDING DEVICE Filed Jan. 31, 1945 2 Sheets-Sheet lINVENTOR 1W4 Van 0S ORNEY May 15, 1951 F. VAN EPS. 2,553,392

RECORDING HEAD FEEDING DEVICE Filed Jan. 51, 1945 2 Sheets-Sheet 2 Ilifii lllllll a I W j ENTOR v I Ikea Van/E 05 19 10 EQ QW TTORNEYPatented May 15, 1951 UNITED STATES PATENT OFFICE RECORDING HEAD FEEDINGDEVICE Fred Van Eps, Plainfield, N. J.

Application January 31, 1945, Serial No. 575,398

Claims.

This invention relates to sound recording apparatus and the like of thetype having a cutting head moving across the record blank as it isrotated and more particularly to improved means for driving the feedscrew for the cutting head.

In the production of disc sound records by the type of apparatus towhich the invention applies, the record groove is formed on the discblank as a succession of convolutions by the cutting head moving acrossthe blank as the latter is rotated by the supporting turn table. Thecutting head is mounted in a carriage which is movably supported on acarrier. The carrier is provided with a feed screw which operativelyengages the cutting head carriage to move it along its path.

It has been found desirable to have a sound recording machine in whichthe drive mechanism for the feed screw can quickly and easily bedisengaged. It is also desirable to be able to quickly and easilydisengage the cutting head from the record blank at any point of itstravel to increase its life.

Modern conditions also demand that a sound recording apparatus includemeans for changing the regular rate of feed of the recording head acrossthe disc record blank. An important, if not the principal, reason is touse the same machine for making records for different purposes,requiring difierent groove characteristics. So, for instance, ordinarycommercial phonograph records are recorded at approximately '78revolutions per minute and with 90 to 100 grooves per inch leaving asubstantial wall between adjacent grooves, while records for electricaltranscription purposes are usually recorded at 33 /3 revolutions perminute and are made with their sound grooves closer together.

Another object is to provide means for immediate and easy disengagementof the cutting head from the disc blank at any point of its travelacross the blank.

It is therefore among the objects of the invention to provide animproved mechanism for driving the feed screw which can easily beadjusted with respect to the rate of speed.

A further object is to provide means for the aforesaid purposes whichare simple and inexpensive in constructions and which can easily beattached to any turn table.

Other objects and advantages inherent in the invention will becomeapparent from the following specification taken in conjunction with theaccompanying drawing and which discloses by way of example an embodimentof the inventive idea.

In the drawing:

Figure 1 is a plan view of a recording apparatus according to theinvention having a portion cut away.

Figure 2 is a sectional view taken along the line 2--2 of Figure 1.

Figure 3 is a sectional view taken along the line 33 of Figure 1 showingthe cutting head and its carriage.

Figure 4 is an end view partially in section showing the drivemechanism.

Figure 5 is a section taken along the line 55 of Figure 1.

Referring in greater detail to the accompanying drawing, the recordingapparatus includes a turn table H] which may be driven by any mechanismusual in the art. The cutting head ll, equipped with a recording stylusi2, is supported by the carriage generally indicated at [3, and which isimpelled across the record [4 by the feed screw l5 during the operationof the apparatus.

The feed screw [5 is rotatably mounted in the carrier generallyindicated at It between the brackets i1 and 18. The bracket IT is spacedabove the turntable It) and substantially opposite the center thereof bythe arm 20, which is anchored to the base 19 at the side of theturntable so as to permit free rotation of the latter. Similarly, thebracket i8 is mounted to the base I9 by means of the foot 2!.

The carrier It is also provided with a base plate 22 which extendsbetween the brackets IT and I8.

The cutting head carriage l3 comprises a top plate 23 which is slidablyand rotatably mounted on the tie rod 24 by means of the sleeve 25. Thetie rod 2 3 is in turn mounted in the brackets ll and I8.

The carriage I3 also comprises a face plate 26 to which are pivoted thebars 21. Between the bars 2'! are the spacers 23 and 29. A plate 33 ispivotally connected to the bars 21 between the outer ends thereof and isprovided with a pair of grooves to which the cutting head ii is securedby means of screws 3!.

The pressure exerted by the recording stylus l2 upon the record blank ii may be controlled as desired by means of the spring 32 and the setscrew 33 on the arm 35 extending from the face plate 26.

The weight of the cutting head also may be counterbalanced by the weight35 which is connected to the lever arm 3% over the pulley 37.

The recording stylus i2 can easily be brought out of and into contactwith the record by means of the cam lever 31 which is mounted on theface plate 26.

The means for actuating the feed screw to move the recording stylusacross the record I4, comprise a gear wheel 38 which is operativelyconnected to the feed screw i5 by means of an over running clutchmechanism generally indicated at 39, and the worm 49 on the shaft 4!which at its other end is provided with a friction wheel 42. Thisfriction wheel 42 functionally engages the friction disc '43 of thesleeve 44 which is mounted over the centering pin 45. The sleeve 44 isalso provided with a driving flange 49 which engages the record so as tobe rotated thereby. Alternatively, friction wheel 42 may directly engagethe top of the record in which case the driving flange 46 and thefriction disc 43 carried thereby may be dispensed with.

Describing the aforesaid means in greater detail, the gear wheel 38together with the disc 41 are rotatably mounted on the stub shaft 48 ofthe feed screw I5. On this stub shaft 48 is also fixedly mounted theratchet wheel 49 of the clutch mechanism as for example, by means of thescrew '56. The clutch mechanism also includes the pawl 5! which ispivoted to the disc 41 normally urged into engagement with the ratchetwheel 49 by the spring 52. With the described construction it will beclear that as the worm gear 36 is rotated by the worm 49 it acts throughthe ratchet wheel 49 and pawl 5! to rotate the stub shaft 48 and thefeed screw [5 at a fixed speed relative to the rate of rotation of theturntable [9, This relative rate of speed can be varied by moving thefriction wheel 42 towards and away from the center of the friction disc43. For this purpose the friction wheel is adjustably mounted on theshaft 4| by means of the set screws 53.

It will also be seen that by reason of the over running clutch mechanismthe friction wheel 42 can easily be raised out of engagement with thefriction disc 43 for the purpose of adjustment without the feed screwbeing rotated.

The shaft 41 is journalled in the bearing blocks 54 of the arm 55 whichalso is rotatably mounted on the stub shaft 48 together with the gearwheel 38.

The bearing blocks 54 may also serve as weights to hold the frictionwheel 42 in engagement with the friction disc 43.

' As the feed screw is rotated it impels the carriage l3 along its path.To this end the car--. riage is provided with a thread engaging plate 56which is carried by the bracket 57 and which is in turn mounted on thesleeve 25.

The apparatus disclosed also includes means for manually operating thefeed screw I5v at a higher rate of speed then is possible with theregular driving means disclosed herein. To this end the shaft 57 of thefeed screw is provided with a gear 58 which meshes with a larger gear59. This latter gear 59 is mounted in the bearing block 66 on thebracket l8 and may be rotated by the crank 6|.

By virtue of the over running clutch mechanism previously described, itwill be seen that by manual operation of the crank 6|, the feed screw 15can be rotated at a speed greater than that normally imparted to it bythe turn table drive so that the recording head can be moved across therecord blank at a much higher than normal speed to provide a high pitchcross over groove from one recorded zone to the start of another or froma recorded zone to a terminal circle or the like.

The apparatus according to the invention also includes means fordisengaging the thread plate 56 from the feed screw l5 at any point ofits path. To this end a rectangular bar 62 is provided which is pivotedexcentrically between the brackets l1 and I8. In other words, this barconstitutes a toggle mechanism for lowering and raising the carriage I3. For this purpose, the carriage is provided with an adjustable setscrew 63 having a head which normally engages the bar 62. When thestylus is in recording position on the disc blank the bar will be in theposition shown in full lines in Figure 3. On the other hand, when theplate 56 is disengaged from the feed screw l5, the carriage will be inthe position shown in dotted lines.

The bar 62 may be turned by the handle 65 against the'pressure of thespring urged plunger 66 which is mounted in the base plate 22.

The apparatus according to the invention also includes means forautomatically disengaging the recording head from the record when thecarrier comes to the end of its path. These means comprise an arm 6?which is fixed to the bar 2? at a predetermined angle and the bevelledmember 63 mounted on the bracket H. The arm '67 and the member 68 are sorelatively adjusted that the arm 6'! will engage the bevelled edge ofthe member 68 as soon as the carriage has come adjacent the end of itspath. Further movement will then cause the recordinghead to rise out ofengagement with the recording blank due to the pivotal mounting of thebars 21 and '28. The pivotal movement of the bars 27 and 26 may belimited by the stop 67 abutting against the plate 26.

It will be understood that this description has been given by way ofexample and not by way of limitation. On the other hand, the inventionmay lend itself to a variety of expressions within the scope of theappended claims.

What is claimed is:

1. A recording apparatus comprising a turntable for supporting a recordduring the recording operation, a record grooving device, a feed screwfor moving said grooving device radially across the record as the latteris rotated, means for driving said feed screw, said means including aworm gear carried by said feed screw, a disc mounted centrally on saidrecord, a shaft extending perpendicularly to said feed screw, a worm onsaid shaft meshing with said worm gear and a wheel on said shaft forfrictionally engaging said disc, said shaft being rotatable about saidfeed screw in a vertical plane whereby said wheel may be disengaged fromsaid disc.

2. A recording apparatus comprising a turntable for supporting a recordduring the recording operation, a record grooving device, a feed screwfor moving said grooving device radially across the record as the latteris rotated, means for driving said feed screw, said means including aworm gear rotatably mounted on said feed screw, a clutch mechanism forconnecting said worm gear operatively with said feed screw to rotate,with said feed screw in one direction, a shaft extending perpendicularlyto said feed screw, a worm on said shaft meshing with said worm gear, adisc centrally mounted on said record, a wheel on said shaft forfrictionally engaging said disc, and a lost motion device associatedwith said clutch mechanism whereby said wheel may be disengaged fromsaiddisc.

3. A recording apparatus comprising a turntable for supporting a recordduring the recording operation, a record grooving device, a feed screwfor moving said grooving device radially across the record as the latteris rotated, means for driving said feed screw, said means including aworm gear rotatably mounted on said feed screw, a clutch mechanism forconnecting said worm gear operatively with said feed screw to rotatewith said feed screw in one direction, a shaft extending perpendicularlyto said feed screw, a worm on said shaft meshing with said Worm gear, adisc centrally mounted on said record, a wheel on said shaft forfrictionally engaging said disc, a lost motion device assooiated withsaid clutch mechanism whereby said wheel may be disengaged from saiddisc, and means for raising said grooving device out of engagement withsaid record.

4. A recording apparatus comprising a turntable for supporting a recordduring the recording operation, a record grooving device, a feed screwfor moving said grooving device radially across the record as the latteris rotated, said feed screw extending eccentrically of the record, meansfor driving said feed screw, said means including a worm gear rotatablymounted on said feed screw, a clutch mechanism for connecting said Wormgear operatively with said feed screw, a disc centrally mounted on saidrecord, a shaft extending radially with respect to said record, a wormon said shaft meshing with said worm gear, a wheel on said shaft forfrictionally engaging said disc, a st motion device associated with saidclutch mechanism whereby said wheel may be dis-engaged from said discand means for raising said grooving device out of engagement with saidrecord.

5. A recording apparatus comprising a turntable for supporting a recordduring the recording operation, a record grooving device, a feed screwfor moving said grooving device radially across the record as the latteris rotated, said feed screw extending eccentrically of the record, meansfor driving said feed screw at variable speeds, said means including aworm gear rotatably mounted on said feed screw, a clutch mech anism forconnecting said worm gear operatively with said feed screw, a disccentrally mounted on said record, a shaft extending radially withrespect to said record, a worm on said shaft meshing with said wormgear, a wheel adjustably mounted on said shaft for frictionally engagingsaid disc, a lost motion device associated with said clutch mechanismwhereby said wheel may be disengaged from said disc.

FRED VAN EPS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,027,350 Mikorey May 21, 19121,399,239 Ahearn Dec. 6, 1921 2,340,658 Goldman Feb. 1, 1944 2,350,490Berliner June 6, 1944 FOREIGN PATENTS Number Country Date 436,157 FranceMar. 20, 1912 270,085 Germany Feb. 6, 1914 359,532 Great Britain Oct.22, 1931 370,418 Great Britain Apr. 4, 1932

